1. Field of the Invention
The present invention relates to an optical scanning apparatus for irradiating a scanning light beam onto a surface of an image carrier, and to an image forming apparatus including the same.
2. Related Art
An electrophotographic process is used in such a type of image forming apparatus. A polygon mirror is provided inside a housing body. The polygon mirror is configured to perform deflection scanning in a predetermined direction of scanning light beams emitted from a plurality of light sources. The scanning light beams are irradiated onto image carriers that are charged in advance with electrostatic charges, for example, onto surfaces of photosensitive drums. In this manner, electrostatic latent images are respectively formed on the surfaces of respective photosensitive drums. Toner images corresponding to respective colors are transferred and fixed onto a sheet of paper.
In this connection, the polygonal mirror is driven by rotation of a motor shaft. When a vibration occurs as a result of driving of the polygonal mirror, a vibration is induced at a scanning (imaging) position of a scanning light beam. Accordingly, it is likely that a writing position of an image by the scanning light beam becomes unstable (an occurrence of a jitter image). As a result, a technique has been developed to suppress the production of such a jitter image.